Delft University of Technology of University Delft

OYSTER Big ideas from small particles research in brief

OYSTER Why neutron research? are released when atomic nuclei split. These extremely tiny a penetrating look particles penetrate deeply into material exposed to them. By measuring changes into matter in the neutrons’ speed and direction when they collide with atoms, we are able to look inside materials while the materials themselves remain intact. With the knowledge thus derived, we gain an idea of how materials originated and the processes which play a role. This allows us to change materials according to our OYSTER is the project that will make the specifications and give them the best properties for their function. research reactor of the Reactor Institute Delft (RID) considerably broader and more precise How does this neutron research in its applicability. With OYSTER, the neutrons work now? The neutrons produced through atomic generated in the reactor are cooled by a device fission in the research reactor are ”let containing liquid hydrogen, slowed down and loose” on materials. Around the research reactor are numerous extremely made steerable in beams. This makes new and advanced and mostly unique instruments better measurement techniques possible, even for making measurements. Neutrons have not only the desirable property allowing us to monitor the production of materials of penetrating deeply into materials, and nutrients in real time. they also have the vexing trait of being difficult to control. They cannot be steered with electrical or magnetic fields. Focusing them with lenses also has very OYSTER offers enormous benefits for little effect. The neutrons simply go every which way. international science, health care and industry. What major improvements will OYSTER bring? These are numerous. There is enormous benefit in being able to better manipulate neutrons despite their The RID is setting the pace worldwide with the development physical elusiveness. New measurement and production of instruments for research using neutrons. possibilities arise and existing methods These tools are widely used in research centers. Since will be improved a hundredfold. experimental and fundamental research programs are possible at the research reactor in Delft, the reactor plays an indispensable role among major international institutions. After OYSTER, this position will be strengthened by more research, greater precision, and greater -off benefits for society.

OYSTER’s new capabilities ensure: n continuation of our edge among top international institutes n a boost for scientific research at the TU Delft n a boost for product development in the Netherlands and far beyond n development of more effective treatment methods in health care n new possibilities for energy generation and storage

The OYSTER project (Optimized Yield – for Science, Technology & Education – of Radiation) requires an investment of approximately 20 million euros and will be operational in 2012.

1 OYSTER The improved reactor RID: Knowledge Center & Heat production OYSTER Innovator better, faster and more precise 3 MW The Reactor Institute Delft is a magnet Speed what does it for scientists. Rising talent as well as measurements of cold neutrons esteemed scientists are attracted to 500 m/s cutting edge research with unique Water function 1: Water slows down fast neutrons deliver? instruments. Intensity of cold neutron beam One of the three neutrons [4] (on page 4) released by must split another uranium 1 billion neutrons Through OYSTER, major limitations atom to keep the chain reaction going (the other neutrons are available for experiments). The speed per s per cm2 in the current neutron technology are of these fast neutrons is so great (20 million m/s) that almost all neutrons fly off without hitting a removed. Currently, ”warm” snapshots uranium nucleus. When the reaction takes place in water, the neutrons are only made at a short distance from collide with the water molecules and are slowed so dramatically the source because that is the only (to 2000 m/s) that they are able to react with the uranium place enough neutrons can be captured. nuclei. Without water no chain reaction occurs, and More neutrons, more power, more speed, and Through OYSTER, scientists will be much the nuclear fission stops. Water pool fundamentally better results. This is the best way less hindered by these limitations. With The reactor core sits the five existing and four advanced to describe OYSTER. It is a logical consequence in a water pool instruments still to be built, the (depth 8 m, volume of the success and the continuing further measurement capabilities will become 250 m3). development of the Hoger Onderwijs Reactor that more precise and more versatile. The thickness of Measurements can be made with both the concrete wall became operational in 1963. ”warm” and ”cold” neutrons; snapshots varies from 1 to as well as process-related findings can Circa 10 m about 2.5 m. be established. With OYSTER, the neutron source is coupled to a coolant of liquid hydrogen. At extremely low temperatures (250 degrees The RID is part of an international network of top institutes that procure below 0 Celsius), the properties of neutrons change in such a OYSTER EXPANSION Neutrons knowledge and instruments in Delft for way that they can more easily be guided and directed. In a box More power The 100 million billion a (production) process is simulated (temperature, pressure, their own research. The RID has been neutrons that are movement, mixing). The neutrons are steered crossways asked to contribute to the European generated every neutron institute under development, the The thermal power (heat through the box, and we see how the material being studied second in the reactor European Spallation Source. For a large production) of the reactor reacts to the treatment – in some cases even when changes will be increased from 2 to core fly off in all group of (international) companies, the occur quickly. 3 MW. By splitting more directions. Neutrons RID is of vital importance in developing uranium per second, 1.5 are uncharged products for the food industry, times more neutrons are particles and microelectronics, steel and plastics generated. About 3 grams therefore cannot be production, etc. What does OYSTER deliver? of uranium are then used steered with per day. magnets. The potential is vast. For example, through OYSTER we can see In the health care sector, the Reactor in real time: Institute Delft works with research hospitals in developing diagnostic n how hydrogen is stored in special metallo-organic buffers methods and treatments for fighting n how ultrathin coatings peel from surfaces Beam tubes cancer and other diseases. n how foods change their structure through movement, cooling Researchers want to conduct experiments with neutrons. Six beam Water vapor or heating. We therefore learn more about curdling and In the energy sector, neutron research tubes (diameter 20 cm) must lead the coagulation processes, important for the development of diet leads to better methods of storing neutrons from the pool to the experiments. foods. energy with hydrogen and batteries. n under what circumstances types of steel and plastic attain Neutrons that fly more or less straight into the their optimal properties beam tubes will reach the experimental setup. All other neutrons fly through the tube wall and are absorbed by the tube n under what circumstances and how the magnetic properties walls, the water and the concrete. Through OYSTER, about one in of materials change every million neutrons will reach an experimental setup. n how dune sand behaves under changing conditions so that we can make judgments about our sea walls n how change processes occur in mixtures such as paint Primary cooling circuitSecondary cooling circuit

Water function 2: Water cools the reactor core RESEARCH REACTOR All heat released by the nuclear fission is led off through the water in the In a normal nuclear plant, the heat released by nuclear pool [5]. A pump ensures circulation (288 m3/h) through the pool. The fission is used to generate steam. The steam drives cooling water is suctioned off via a funnel along all the fuel plates. The turbines which produce electricity. warm water releases its heat in a heat exchanger [6] and once cooled The goal of the Delft reactor is to generate neutrons o (max. 40 C), flows back into the pool [7]. The secondary cooling system for conducting scientific experiments. discharges its heat to the environment [8] through evaporation into the air.

2 OYSTER 3 OYSTER COLD NEUTRONS New control rods Ventilation shaft OYSTER EXPANSION Six aluminum tubes filled with boron carbide can be inserted into the reactor Ventilators suck the air out of The main advantage of ”cold” neutrons is their greater Result of planned expansion De vernieuwde reactor core. If two of these control rods are lowered completely into the core, they the hall [2] and conduct it via a tendency to remain in the beam guides; consequently, 100 Warmteproductie absorb all free-flying neutrons and thereby stop the nuclear fission. If a filter and a ventilation shaft times more neutrons reach the experiments than with ”warm” Clean air The total neutron intensity of the modified reactor will be 3 MW power outage occurs, the control rods fall into the core by themselves. (height 60 m) outside. neutrons. A second advantage is that with the greater 100 times greater than that of the current reactor, allowing beter, sneller en preciezer meten Detectors measure the vented wavelength of ”cold” neutrons, larger structures become larger structures or smaller details in studied materials to Snelheid air for the presence of visible. A third advantage is that the ”cold” neutrons move less become visible than we can currently see. In addition, koude neutronen radioactive compounds. Waterfunctie 1: Water remt snelle neutronen af quickly through a test material, allowing more precise measurements can be taken 100 times more quickly than 575 m/s As soon as radioactivity is measurements. To make cold neutrons, the current reactor is currently the case. measured, the gastight valves Eén van de drie neutronen die bij de kernsplijting vrijkomt moet een volgend uraniumatoom Intensiteit koude must be fitted with a neutron cooler [1] which slows the fast, close off the airflow and the splijten om de kettingreactie aan de gang te houden (de andere neutronen zijn beschikbaar neutronenbundel ”warm” (40 oC) neutrons to slower, ”cold” neutrons (-250oC). reactor is shut down. voor experimenten). De snelheid van deze snelle neutronen is zo hoog (20 miljoen m/s) dat 1 miljard neutronen The measurements will then take much less time and will yield bijna alle neutronen wegvliegen zonder een uraniumkern te raken. per s per cm2 more information. Door de reactie in water uit te voeren botsen de neutronen met de watermoleculen waardoor ze Reactor building zo sterk worden afgeremd (tot 2000 m/s) dat In the airtight steel hall [3] ze wel kunnen reageren met de uranium- (diameter 25 m, height 28 m) kernen. Zonder water vindt er geen a lower air pressure ensures kettingreactie plaats en stopt Waterbassin Reflector elements that no air can leak into the de kernsplijting. De reactorkern staat Beryllium reflectors environment. in een waterbassin (a metal that absorbs (diepte 8 m, volume almost no neutrons) 250 m 3 ). De dikte must reflect as many van de betonnen free-flying neutrons as wand varieert possible to the fuel van 1 tot elements. Circa 10 m circa 2,5 m. Neutrons

Beam guides Uranium 70 cm OYSTER UITBREIDING Neutronen Hoger vermogen De 100 miljoen x miljard neutronen OYSTER EXPANSION OYSTER EXPANSION Het vermogen (warmte- die elke seconde in de reactorkern New reactor configuration Neutron cooler productie) van de reactor wordt verhoogd van 2 naar worden opgewekt, vliegen alle kanten The new reactor core has nine fuel elements (instead of Right next to the nuclear reactor a 3 MW. Door meer uranium per seconde te splijten, op. Neutronen zijn the current 20 elements). reservoir is placed containing liquid ongeladen deeltjes o worden 1,5 keer meer hydrogen (temperature -250 C). en kunnen daarom The neutrons that are released in the neutronen opgewekt. Current fuel plates Per dag wordt dan circa niet met magneten reactor fly through the cold hydrogen, worden gestuurd. Each fuel element (8 x 8 x 60 cm) consists of 19 fuel which slows their speed from 2000 m/s 3 gram uranium verbruikt. plates. A fuel plate is an airtight aluminum box to 500 m/s. The reservoir consists of containing a thin sheet of uranium silicide. The reactor an aluminum tank with inlets and core contains a total of 4 kg of uranium. outlets leading to a heat exchanger. Bundelbuizen Onderzoekers willen experimenten Nuclear fission in the fuel plates waterdamp Neutrons fly through the aluminum cladding and cause doen met neutronen. Zes bundelbuizen nuclear fission of the uranium. All isotopes produced by (diameter 20 cm) moeten de neutronen High-energy radiation Experimental hall the fission reaction remain in the fuel plate and never vanuit het bassin naar de experimenten end up in the water. The high-energy radiation is largely geleiden. Neutronen die vrijwel parallel aan de absorbed by the aluminum cladding (the rest by the buisoriëntatie de bundelbuizen in vliegen, komen bij Aim of the reactor: neutron research water). The energy generated is released into the water Uranium nucleus de experimenteeropstellingen uit. Alle andere neutronen In the measurement instruments around the research that flows between the plates (3 mm space between the vliegen door de buiswand heen en worden geabsorbeerd door reactor, neutrons are directed at a piece of test material. plates). de buiswanden, het water en het beton. Ongeveer één op de The neutrons change speed and direction as they collide miljoen neutronen zal in OYSTER bij een experiment aankomen. with atoms in the test material. Through the diffraction or scattering of the neutrons measured, we obtain an Primair koelcircuit Secundair koelcircuit Nuclear fission of uranium Three free ”image” of the composition and structure of materials at Atoms consist of a cloud of negatively charged particles neutrons (electrons) that orbit around a nucleus of positive particles the atomic level which cannot be achieved in any other Waterfunctie 2: Water koelt de reactorkern ONDERZOEKSREACTOR (protons) and uncharged particles (neutrons). When a way. Alle warmte die bij de kernsplijting vrijkomt, wordt door het bassinwater In een reguliere kerncentrale wordt de warmte die neutron from outside collides with a uranium nucleus and 3 afgevoerd . Een pomp zorgt voor een circulatiestroom (288 m /h) vrijkomt bij kernsplijting gebruikt om stoom te the atom takes that neutron into its nucleus, the uranium OYSTER EXPANSION door het bassin. Het koelwater wordt via een trechter onder de genereren. De stoom drijft turbines aan waarmee nucleus splits into two smaller nuclei and three neutrons. Free neutron roosterplaat langs alle splijtstofplaten gezogen. Het warme water geeft elektriciteit wordt opgewekt. Het doel van de Delftse The mass of the fission products is smaller than that of the New instruments zijn warmte af in een warmtewisselaar en stroomt afgekoeld reactor is neutronen op te wekken om fissionable material because the reaction converts some o (max. 40 C) terug het bassin in. Het secundaire koelsysteem staat zijn wetenschappelijke experimenten mee uit te voeren. mass into energy. This energy is released as kinetic energy In addition to the five existing instruments, three new warmte af aan de omgeving (verdamping in de lucht). De vrijkomende warmte zal nuttig worden gebruikt. and high-energy radiation. Fission of one gram of uranium Proton instruments will be built which only work with ”cold” releases 24.000 kWh of energy. This is equivalent to neutrons. These new instruments will permit measure- burning 2.500 liters of gasoline. Fission product ments that are currently impossible.

4 OYSTER 5 OYSTER ROG is an existing instrument that will External radiation Liposome perform 100 times better with OYSTER. High-energy radiation [1] Liposomes are small, hollow spheres Apart from layer thicknesses themselves, the destroys tumor cells. External of fat (diameter about 0.01 mm). roughness of layer surfaces will also become radiation of a patient has the The wall consists of a double layer of Better visible. major disadvantage that the molecules whose head dissolves in radiation also destroys healthy water and whose tail dissolves in fat In the production of chips, mirrors are used cells. (comparable to a soap). semiconductors The hollow liposomes are well suited for directing extreme-UV light. The coatings to transporting a medicine [2] on these mirrors are extremely critical: the through the body. The fat sphere and artificial hips slightest film or residue dramatically reduces Making a liposome with a then works as a packaging which the reflection. This can be examined using the radioactive core keeps the medicine isolated until it with ROG ROG. A capsule of liposomes containing a arrives at a diseased cell. There the For an artificial hip, the quality of the coating holmium atom, for example, in their package must open so that the determines whether or not it will be rejected hollow interior, is placed next to the medicine can do its work. by the body. With ROG the quality of this sort reactor core via a tube [3]. The neutrons of coating can be determined with extreme make the holmium atom radioactive. The fat An instrument that promises improved products in numerous precision, and any deterioration can be sphere absorbs almost no neutrons, and the sectors is the Reflectometer for Surfaces and Interfaces monitored. radioactivity induced in the fat is so short- Research (ROG). This instrument can look at the thinnest lived that it has already disappeared before layers and coatings. ROG measures how neutrons reflect at the sphere leaves the reactor. a grazing angle of incidence. From this can be deduced how carbohydrates bind to various materials, how magnetic layers on tapes and hard drives behave and how coatings adhere to materials for artificial hips.

Liposome diameter 0.01 mm

Gamma radiation destroys liposomes The reactor core gives off not only neutrons but also gamma radiation. This gamma radiation can destroy the structure and the wall of the fat spheres, releasing the holmium atoms [2] from OYSTER will give this medical development their packaging. In order to prevent this, a substantial boost. CNIF allows extremely the fat sphere is now irradiated at a site pure nuclear medicines or therapeutic far from the reactor core where there is materials to be made. The current generation little gamma radiation, but also few Better of radionuclides contains many inactive Neutrons neutrons. More neutrons would make the components. These sometimes have holmium radioactive more quickly. treatment of undesirable chemical properties with adverse Cold source health effects. Or they needlessly saturate the tumor being treated, thus reducing the OYSTER EXPANSION: CNIF cancer effectiveness of the radiation. Cold neutron source Liposomes With CNIF we are able to separate out the Internal radiation with CNIF The new cold source [4] will inactive molecules in radionuclides, leaving A liposome containing a fulfill a double function. behind a practically pure and extremely radioactive atom in its First of all, the cold source slows hollow interior is injected effective radioactive material. This allows for a down the neutrons so that they into the body. Within a more effective combating of cancer cells and collide more frequently with the minute the liposome With the Cold Neutron Irradiation Facility (CNIF), materials can a reduction in side effects. holmium atoms. arrives at its destination be made radioactive. This instrument is placed strategically Second, the reservoir of liquid and becomes wedged behind the cold source, where it receives many cold neutrons The manufacturing of this sort of ”nuclear hydrogen functions as a shield inside a tumor. The and little gamma radiation. CNIF thus makes complex structures medicine” must take place in close proximity against gamma radiation. The radioactive atom briefly radioactive without destroying them. to treatment centers. The radioisotopes quantity of neutrons reaching the releases high-energy liposomes is maximized without are often short-lived and must therefore be radiation. The radiation destroying the fat sphere with This capability offers useful perspectives for new treatment applied in a treatment within a few hours; stops the growth of the the damaging gamma radiation. methods for serious forms of cancer. The Reactor Institute Delft otherwise they lose their effectiveness. tumor cells while the This allows more effective is currently working with research hospitals in the development surrounding, healthy cells medicine packages to be High-energy of a new generation of radioisotopes. These are, in a manner Tumor cells radiation remain unharmed. of speaking, nuclear medicines that fight cancer cells very produced. precisely without damaging healthy tissue. Tumorcellen

6 OYSTER 7 OYSTER Texture in storage Scattering through fat OYSTER EXPANSION: SESANS In the ideal case, the texture When a neutron moves through in a sealed tub of cheese cheese spread and collides with a Better measurement spread is fixed (from the fat sphere, the neutron changes With “warm” neutrons, SESANS factory to the consumer) [6], direction [9]. The path length of Innovative can measure 10,000 times faster so that all fat spheres remain the neutron through the second than the classical apparatus with a in place and the cheese therefore changes, projection screen, allowing us to food products cannot separate into a fat making the neutron swing less to see structures 100 times greater later and a water layer. the right than to the left. The final (to 10 micrometers). With long orientation of the neutron wavelength “cold” neutrons the with SESANS has now changed. size becomes 20 micrometers; Polarized neutrons OYSTER also allows a measure- Using a crystal and a mirror, all the ment to be taken in 1/100th the neutrons of one speed and orientation time. are selected [7].

The Spin Echo Small Angle Neutron Scattering facility (SESANS) Fat spheres in water is a neutron polarizer. This instrument measures the scattering Cheese spread consists of of the neutrons. The polarized neutrons change direction small spheres of fat and through collision with atoms in the research material. This water. The size and scattering angle is measurable through the trick of converting consistency of the fat it into rotation. This trick allows supersmall scattering angles to spheres determine whether be measured, shedding light on the larger-scale structure within cheese tastes ”creamy.” the research material. A loose distribution of fat spheres [1] of about 1 micrometer is experienced Food products are being prepared at ever greater distances as creamy, while a clump of from the places where they are consumed. The composition of spheres [2] larger than 10 foods is also being more precisely tuned to the dietary needs of micrometers is experienced Guide field western consumers. With SESANS, we can look into the food to as grainy. It is not possible observe how it is affected by preparation. with a microscope to see the behavior of fat spheres Inclined With OYSTER the possibilities are greatly increased because we inside cheese because it is magnetic fieldCheeseNeutron counter can observe changes in real time. We can, for example, literally not transparent. But with watch milk turn into cheese and thus learn to predict what SESANS, it is possible. the effect of a given treatment on this food will be. Cooling, Opposite fields Seeking maximum polarization Size of spheres heating, stirring and shaking, centrifuging or ripening. With this The polarized neutrons move through two inclined By increasing the strength of the From the size of the magnetic field, the knowledge we can also take post-manufacturing effects into Unsteerable neutron Magnetic field planes with opposite magnetic fields. Regardless of magnetic fields, a moment arises when speed of the neutrons and their speed account. A neutron has no charge and the neutrons’ angle of incidence, the path traveled the scattered neutron has swung of rotation, the difference in path does not change its direction of in both planes is equally long, thus a neutron swings exactly one time fewer to the right length through the magnetic fields and With OYSTER we can ensure that an ice cream bar tastes even movement [3] when it moves just as often to the left as to the right in the two than to the left. When the neutrons therefore the scattering angle of through a magnetic field. better after it has left the factory. The manufacturer can make fields. At the end of the measurement device [8], were selectively scattered at that the neutron can be calculated. The the number of neutrons having the starting more intelligent use of the knowledge that the ice cream leaves angle, SESANS sees a maximum distribution of preferred angles reveals orientation is measured (= polarization). If the polarization from the scattered the size of the spheres in the sample, a cooled space several times during transport, so that when we neutrons have not collided, all neutrons will still be neutrons having taken on the the distances between the spheres and consume the ice cream, it is in optimal condition. pointing in the same direction, and the polarization same orientation as the unscattered the wall thickness of a hollow fat With OYSTER the composition of food can also be changed and is maximal. neutrons. sphere. adapted for a healthier diet. Food manufacturers are currently investing in research on whether fat spheres can be replaced by bubbles containing no fat but only water. Food then becomes cheaper, because fat is more expensive than water. At the same time, these ”light” food products will taste good because they NEUTRONS Deriving sphere size from shadow are perceived as creamy. This is both a commercially interesting pattern and a healthy development. RESEMBLE LIGHT Scattering Because light is a wave, light shining angle through the slit casts a pattern of shadows SESANS measures the Slit on the screen behind much larger than the scattering (change in slit. From the distances between the Neutron direction) of neutrons ”scattering angle of maximum light resulting when a neutron intensity,” the size of the slit can be (for example) collides with calculated. If there are several slits, the a fat sphere.This scattering wave patterns of the slits intensify (much Neutron spin is comparable to the light) or dim (less light) one another. The Because a neutron consists of a positive, a negative and scattering of light through Sphere preferred angles then provide information a neutral quark, a neutron changes orientation (like a a slit: a neutron behaves distance on the distances between the slits and their compass needle) [4] in a magnetic field. A neutron also as a particle but also arrangement (ordering). This works just has an inherent spin, an angular momentum of constant has wave properties, the same with SESANS, except that light size. When a neutron enters a magnetic field, the just like light. intensity is not measured, but the number ”spinning compass needle” swings (precession) [5] of neutrons (=intensity) that has changed around the direction of the magnet’s field. direction and therefore orientation.

8 OYSTER 9 OYSTER OYSTER EXPANSION: NDF New instrument

Porous metallo-organic frameworks are composed Better of organic molecules bound together by metal Hydrogen is a promising atoms. Hydrogen atoms [1] end up in the open energy storage material for solar cells spaces in the framework. Researchers want to the future. Hydrogen can be understand how the hydrogen atoms nestle in stored as a gas or liquid in these hollow spaces. Specific atoms can stimulate a tank (like liquid propane). with [2] or block the storage of hydrogen atoms. With It is also possible to store a microscope we cannot look into a material at hydrogen in solids, such as POSH 2D-ACAR the atomic level. With NDF we can. metallo-organic materials.

This series of existing and well-known instruments works with Neutron beam Detectors antimatter. The acronym stands for POSitrons at the Higher Measuring the distances between atoms education reactor 2-Detector Angular Correlation Annihilation A warm neutron beam is aimed at a crystalline Radiation. This instrument uses primarily gamma radiation close test material. Two ”choppers” [3] (spinning Test material to the reactor core to generate positrons. wheels with holes in them) allow regular Energy is converted into antimatter that triggers an annihilation pulses of neutrons through (= start time). reaction in the sample to be studied. This is when a particle (electron) comes in contact with its antiparticle (positron) The neutrons are reflected by the planes of and they destroy each other. The energy released from this is the crystal and are absorbed by a number of measurable. Very small variations in the results consequently detectors [4] (=stop time). From the distance shed light on the movement of electrons in close proximity to traveled and the time of flight (=stop time irregularities in the material being examined. plus start time), the wavelength of each neutron is calculated. The wavelength, the reflection angle [5] and the intensity of the This is good news for the solar cell. Performance would be less energy will be lost due to reflection. The reflection show which distances occur between much improved if the solar cell were completely black instead behavior of the electrons close to the defects the crystal planes in the test materials. Special of predominantly blue. With POSH 2D-ACAR we can look into is therefore of great importance. software can then calculate the entire crystal ways to make solar cells black by means of ”defects” in the lattice. crystal lattice. This will also improve the energy efficiency, since

Reflection angle Detector Neutron

OYSTER makes new energy techniques possible. With NDF we can see how and under what conditions hydrogen is stored in metallo-organic materials. These have the More remarkable property of being able to store a larger volume of hydrogen than a hydrogen efficient energy tank. NDF shows where the hydrogen stays in the crystalline structure of the material. Kitchen salt storage NDF is also used in research on energy Measurement of a single crystal of kitchen salt reveals just one distance [6], so that the storage in batteries. Knowledge and crystal lattice is immediately known. with NDF understanding of crystalline structures and the working of various parts of superbatteries are crucial in the development of electric vehicles and decentralized (mobile!) Lattice surface CHARGING AND availability of electrical power. DISCHARGING The Neutron Diffraction Facility (NDF) is playing an important Neutrons reflect strongly off crystalline materials With NDF, the ”empty” crystal lattice of a role in the development of our future energy supply. NDF is a A signal of a reflection off a single atom is not detected. If the atoms are metallo-organic material is measured first, new instrument that works with the characteristic wavelength of arranged in a regular way in crystal planes, and if the pathlength difference and thereafter the situation if hydrogen is ”warm” neutrons. By measuring the reflection of the neutrons between the reflections off the different planes is a multiple of the neutron added. The extra distances ”show” where as a function of the angle it is possible to unravel the structure wavelength, the reflections intensify each other and are measured as an and how the hydrogen atoms are located in of crystals. intense signal by the detectors. the lattice.

10 OYSTER 11 OYSTER With OYSTER these possibilities are expanded Positron source Repair of cracks at the atomic level much further. OYSTER allows us to observe The positron source is Small clusters of copper atoms in the atomic the faster processes in steel production and shoved close to the lattice of aluminum give aluminum alloys their see the appearance and disappearance of reactor core via a mechanical strength. If not all the copper atoms Stronger smaller grains. We see in real time what beam tube. clump together during manufacturing, the free happens in the formation of steel and how copper atoms can act as a filler. As soon as cracks appear at the atomic changes affect it. steel level, for example in an airplane This is interesting to steel manufacturers. wing, free copper atoms [1] Because steel undergoes extensive processing fill the gaps. with PANDA after manufacture, the properties of the product also change. The ability to predict these changes allows one to take them into account in advance. Steel can thus acquire its optimal properties only after pressing and treatment in zinc baths and paint lines. And maintain these properties for years in summer Positrons The Poly Axis Neutron Depolarization Analysis (PANDA) and winter. apparatus is a ”neutron aligner.” Every neutron is a little magnet that can be pointed. The ”aligned neutrons” are sent through Neutrons Magnetic the research material. The exiting neutrons are measured to Test material fields see how much they have ”swung.” We are then able to look into vacuum test space A long coil is materials and see their magnetic structure. wrapped around the The composition of steel thus becomes visible: tightly packed Lifetime detector vacuum tube. grains, some of which are magnetic. The size and composition This coil of the grains change during solidification, but also afterwards creates the from rolling and further working. This whole process can be magnetic field Gamma radiation simulated in the PANDA. Through a better understanding of the that guides processes we can optimize production methods. We can make the positrons to the test judgments about the steel’s strength and even predict when Tungsten grid material. steel will fail. This will allow us to build better bridges and put The positron source consists of a series of safer crumple zones in cars. tungsten grids close to the reactor core. Gamma radiation from the core produces positrons and electrons in the tungsten. An Energy detector electrical field leads the positrons into the magnetic field.

OYSTER EXPANSION: POSH-PALS Recipe for aluminum More positrons What is the right manufacturing method? At what temperature and A cadmium hood [2] absorbs the for how long should aluminum be neutrons that originate from the core. heated? How much copper should From the data provided, the size of the This releases extra gamma radiation be added? Or does another metal work better? With positrons these hollow spaces in a structure can be deduced. that is converted in the tungsten grids Free Positron questions can be answered. Potential fractures then become visible at a into extra positrons, making the positron beam seven times more powerful. copper atom beam very early stage. The instrument can also be Self-healing used in the development of ”smart” materials.

aluminum When free copper atoms are added to Positron and electron disappear Lifetime of positrons aluminum, they fill up the beginning of A positively charged positron is repelled by With the new PALS apparatus, the hairline cracks. In theory, this leads to ”self- the positive atomic nuclei. After the positron lifetime of positrons in defects can with POSH-PALS healing” aluminum: as soon as a fracture has been shot into the test material and be measured. The larger the slowed down, it then seeks places where defect, the longer it takes for a begins, copper atoms repair the damage. + This continues until the copper atoms are atoms are missing. This can be a gap of a positron to meet an electron and + used up. single atom [3] but also the beginning of a annihilate. With extra detectors With POSH-PALS this process can be followed crack. that can precisely measure the annihilation radiation, it can be in real time so that the optimal composition Finally the positron annihilates [4] with one discovered which atoms play a role and lifespan of this self-healing aluminum can of the electrons present around the defect. in the repair. Positrons Higher Education Reactor – Positron Annihilation be determined. This causes both particles to disappear and PALS measurements of self-healing Lifetime Spectrometry: this new instrument shoots antimatter two photons (annihilation radiation [5]) are aluminum will show how many and into a sample to see how long it takes before it meets and released. The existing ACAR-measurement how quickly free copper atoms [6] destroys its negative counterpart. The larger the spaces in a device gives information about the energy reach and fill the open spaces in structure, the longer it will take for this to happen. levels of the electrons in the test material. aluminum.

12 OYSTER 13 OYSTER Determining chemical Detector OYSTER EXPANSION: SNM composition The chemical composition Directing neutrons of objects is interesting to The figure out - for example, With neutrons the composition to determine whether the of an object can be determined pigment of a painting was without destroying it. lie detector really made 300 years ago. To analyze a specific piece it is It is possible to scrape a small necessary to aim the neutrons SNM piece of paint off the canvas to precisely. This is possible with analyze it chemically, but this cold neutrons because they are damages the painting slightly. steerable with hollow glass fibers.

The Scanning Neutron Microscope (SNM) requires a ”cold” Neutron beam neutron beam. Via hollow glass fibers the SNM focuses neutrons at a point on the material to be examined. Some neutrons are absorbed there. The energy released manifests itself as flashes of light. These can be measured. The analysis reveals the Analysis with neutrons details of the composition of the material in the focal point: in When a neutron beam [1] is theory, all elements in the periodic system can be made visible directed at a painting, some in this way. pigment atoms take a neutron into their nucleus and send out This new measuring instrument will make entirely new a very short flash of light [2] applications of neutron research possible. ”Authentication Non-destructive research (high-energy radiation). research” in the world of art and cultural heritage is a promising The main advantage of analysis with The painting does not change neutrons is that it causes no damage to detectably as a result of the field. With SNM, pigments in paintings can be analyzed to the test material, allowing the entire analysis because the neutrons determine whether they came from the master’s palette or surface of a painting to be analyzed only hit one out of every 100 from an art forger of a later period. The same holds true for the millimeter by millimeter. billion pigment atoms. composition of bronze, glass and pottery. Another area of research concerns the organic breakdown of contaminants. It is known that certain organisms (vegetation, bacteria) feed on chemical contaminants. With SNM we can examine how, why and under what conditions organic tissue Glass fibers Focal point Gamma radiation takes up chemical elements and what happens to them The neutrons are led through a bundle of cross-section 0,2 mm subsequently. This also opens up new pathways for medical hollow glass fibers (fiber diameter a few research, such as research into the absorption of contaminated micrometers) to a focal point on the test compounds by the liver and their effects. material. It is impossible to steer warm neutrons with glass fibers.

A germanium crystal as a detector The gamma radiation is absorbed by a germanium crystal [3] (diameter 10 cm). Each emits a different color of gamma radiation. The relationship between the gamma colors and the elements is known. Germanium can detect very precisely the differences in color and intensity of gamma radiation. The germanium crystal converts the gamma radiation into electrical signals which are measured.

Liquid nitrogen The germanium crystal is cooled with liquid nitrogen [4] (-196 oC) to ensure that Neutron only electrical pulses occur as a result of beam the gamma radiation absorbed.

14 OYSTER 15 OYSTER Inter- nationalization

Neutron research has yielded many benefits to modern life. ISIS, Oxford, England & International particle research, such as that conducted in Delft since 1963, has contributed to more effective health care, ILL, Grenoble, France better materials and more precise control of (production) The largest pulsed neutron source in the processes. Through these benefits, our quality of life has world is located in England, while France has improved considerably. the most powerful research reactor in the world. The two enormous research complexes host the world’s top scientists in the field of Within the international particle research community, neutron research. Delft has come to play a unique and indispensable role. ISIS commissions instruments, developed and built for this institute, from the RID. ILL also RID, Delft makes use of Delft knowledge and ideas. The RID complements ISIS through its goals In the Netherlands, the Reactor Institute Delft (RID) is the and capabilities. In Delft, fundamental and academic center for radiation-related research and education. experimental research is conducted that The RID is a partner with national and international academic would not be suitable for ISIS and ILL. On the institutions and contributes to fundamental research in a variety career ladder, RID serves as a portal for ISIS of fields. Through a combination of expertise, the reactor and ILL. itself, the right instruments and a low-threshold accessibility, the RID is also the contact point of businesses seeking innovative applications to enhance the efficiency, safety, and innovativeness of products. The RID employs 150 people. NRG, Petten

Our country has two research reactors. The European Spallation Source reactor of the European Commission in Petten is operated by the Nuclear Research and consultancy Group (NRG). With the reactor’s Europe has so far enjoyed a head start on the rest of the world high power and high radiation levels, the when it comes to neutron research, with ISIS and ILL as trump primary research there is materials research cards. But the United States and Japan are on the verge of into radiation damage, in which materials are completing neutron sources that will be stronger than ISIS. tested for application in high radiation fields. Petten is also a supplier of radioisotopes The European neutron community is preparing to build a pulsed for the medical industry and operates on a neutron source that will surpass all existing sources by a factor commercial basis. of ten: the European Spallation Source. Combining knowledge and expertise on a European scale makes it possible to maintain The research reactor of the RID is oriented our leading position in the world. towards scientific research, the uses of radiation to develop better functional The Netherlands has been asked to contribute to this project materials and compounds. Delft also develops via the RID. The Netherlands will therefore, through the RID, new applications and optimal production play an important role in the development of this European methods for medical radioisotopes. Delft thus research facility. supplies knowledge that can be applied in Petten.

16 OYSTER Delft University of Technology Production date Graphic lay out © © Translation Coördination &text Colofon I F T Mekelweg 15-2629JBDelft P.O. Box 5042-2600GADelft Reactor InstituutDelft TU Delft Designcover Illustrations &text www.rid.tudelft.nl +31 0152786422 +31 0152786744 Februari 2009 Chris Cras Reclame Verdult -Kennis inBeeld Verdult -Kennis www.kennisinbeeld.nl inBeeld, Roberta Hardy Zuid-West 3Communicatie